Heating apparatus



Feb. 28, 1939. w. M. HEPBURN m- AL 2,143,466

HEATING APPARATUS Filed Jan. 2, 1937 ZSnventom w 107. Hepburn 8 T. 14'.N0 nford @ttomeg Patented Feb. 1939 UNITED STATES PATENT OFFICE HEATINGAPPARATUS William M. Hepburn, Ottawa Hills, and Theodore W. Munford,Toledo, Ohio, assignors to Surface Combustion Corporation, Toledo, Ohio,a corporation of New York Application January 2, 1937, Serial No.118,772

- 10 Claims.

Fig. 1 is a small scale View illustrative of the 8 application of thepresent invention;

Fig. 2 is a fragmentary sectional view of a part shown in Fig. 1;

Fig. 3 is a greatly enlarged sectional View of another part shown inFig. 1, 'the view being taken on line 3-3 of Fig. 4;

Fig. 4 is a-sectional view taken on line 4-4 of Fig. 3;

Fig. 5 is a cross section along line 5-5 of Fig. 4.

The radiator tube to be fired is indicated at I and for simplicity ofillustration has been shown as of hairpin type (in Fig. 1) with the freeendsof the tube extending through a wall II of the heating chamberwherein the tube is positioned.

The device l2 associated with one end of the tube I0 is a suctionproducing device which for illustrative purposes has been shown asconsisting of a jet orifice nozzle |4 set to discharge into aneductortube l which forms in effect an extension of the exhaust end ofthe said tube. A pipe l8 having an ordinary shut-01f valve suppliesfluid under pressure to the nozzle l4. As will more fully appearhereinafter, the primary purposeof the device I2 is to draw com bustionsupporting air into the other end of the tube l0.

The device 3 associated with the other end of the tube l8 embodies thepresent invention and briefly stated comprises means for introducinggaseous .fuel into the tube and means for continuously insuring ignitionof the fuel upon its v entry into said tube.

The fuel which is to be burned in the radiator tube I0 is introducedinto the same by a plurality of circumferentially spaced fuel tubes I9leading from an annular gas supply chamber 20 in front of the mouth 2|of the radiator tube, the tubes- |9 being of suiliclent length to extenda substantial distance into said mouth. Fuel gas is supplied to thechamber 28 by a supply pipe 22 provided with a flow regulating valve 22'(see Fig. 1). The chamber 20 is concentrically supported with respect tosaid mouth 2| by a plu-' rality of circumferentially spaced spacerfingers with the atmosphere for reasons 23 which extend from a wall ofsaid chamber to a ring 24- which slips over and is secured to acircumferential ledge 25 at the outer end of said mouth 2|.

The chamber 20 is conveniently formed as part of a metal drum 26 whichat one end converges inwardly as indicated at 21. Extending from andforming in eflect an extension of the converging part 21 is a tube 28which projects a substantial distance into the mouth 2| of the radiatortube II], it being noted that the diameter of the tube 28 is verymaterially less 'than that of the radiator tube. The fuel tubes l9preferably terminate short of the discharge end of the tube 28 and areshown as converging inwardly with respect to the latter, primarilybecause of the fact that the diameter of the annular gas chamber 20 issuch as to require that arrangement when the tubes 9 are straight.However, insofar as the present invention is concerned, the tubes |9might well be angled between their ends so as to, make their respectivedischarge ends extend in parallelism with the tube 28. The tube 28 isshown as apertured between its ends as indicated at 29 for reasonspresently appearing.

The drum 26 serves as a casing for a refractory body 30 through whichextends a passage which intermediate its ends is enlarged as indicatedat 3| to form in effect a chamber. That part- 32 of said passage whichleads to the tube 28 may be termed a throat; the other part 33communicates presently appearing.

Secured to and extending laterally away from.

the drum 26 is a tubular body 34 which serves as a casing for arefractory body 35 having an axial tunnel 36 which at one end opens intothe aforesaid chamber 3| at one side of the axis of the latter asindicated at 31 and which at its other endis open to the atmosphere byway of a flaring mouth 44 formed as part of the body 34.

Supported by circumferentially spaced webs 38 integral with the body 34at the front end thereof isa fuel discharge noggle 39 to which fuel isdelivered by a fuel supply pipe 40 provided with an ordinary hand valve4|. Also supported by the webs 38 is a relatively short mixing tube 42having aflaring mouth. The nozzle 39 and the mixing tube 42 areseparated from each other by a gap 43 to which atmospheric air hasaccess. The jet of fuel gas issuing from the nozzle 39 entrains some airas it flows into the mixing tube 42 and the mixture issuing from thelatter entrains the balance of the air required for complete combustionof the fuel. If desired there may be adjustably mountedon the body ofthe nozzle 39 a bell type damper 4B for restricting the free flow of airto the mixing apparatus in front of the tunnel a.

Combustion of the fuel issuing from the nozzle 39 occurs in the tunnel36 and the hot gases thus produced serve to ignite the fuel issuing fromthe fuel tubes l9. The burner which comprises the tunnel 36 thereforconstitutes a pilot for igniting the fuel issuing from the tubes I9.Bearing in mind that the suction producing device H at the exhaust endof the'radiator tube Ill produces a pull or suction effect at the intakeend of said tube, it will be readily appreciated that the gases suppliedto the chamber II" will flow toward the region of low pressure, that isto say, toward the intake end of the radiator tube by way of the throat32 and tube 28 rather than out to the atmosphere through the passage 33.Although the apparatus would function more or less efliciently even ifthere were no passage 33 in open communication with the atmosphere, orif the outer end of the passage were closed by a damper (not shown)nevertheless the advantages of such a passage are briefly as follows.namely, it serves as a lighting hole through which a flare may beinserted for initially igniting the fuel flowed into the combustiontunnel 38 from the fuel nozzle 39; as an inspection hole for observingwhether the fuel flowing from the fuel tubes I9 is burning properly, andmost important of all it serves as a means for preventing pulsationcoming from the radiator tube ill from blowing out the flame in thecombustion tunnel 36.

By arranging the tunnel 36 to discharge tangentially into the chamber3|, the gases issuing from the tunnel spin around in said chamber withthe result that pulsations from the radiator tube It] cannot readilyblow out the flame of the fuel issuing from the nozzle 39. The radialholes 29 in the tubev 28 may be considered as breather holes whichmaterially dampen the effect of said pulsations on the burner firinginto the chamber 3!.

In some cases, it may be desirable to introduce a small stream of fuelgas into the tube 28 in order to extend the flame issuing therefrom andto this end there is provided a small feed pipe 46 leading from the gaschamber 20 and projecting into the tube'through one of the holes 29 insaid tube 28, the flow of gas through the feed pipev being controlled byany conveniently located valve 41.

What is claimed is:

1. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising an open ended tube having itsdischarge end in the path of flow of fuel into said space, and apressure burner firing tangentially into the tube intermediate the endsthereof whereby the gases spiral around in the tube before emerging fromsaid discharge end.

2. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft, ap-

paratus for maintaining ignition of said fuel irrespective of pulsationsin said space comprising anopen ended tubular body having a dischargeend in the path of flow of fuel into said space, said body having anenlarged chamber intermediate its ends, and a burner firing tangentiallyinto said chamber whereby the gases spiral around in the chamber beforeemerging from the discharge end of said tubular body.

3. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising an open ended tube having itsdischarge end in the path of flow of fuel into said space, said tubehaving a tangential port intermediate its ends, and a pressureburnerfiring into said port whereby the gases spiral around in said tubebefore flowing from the discharge end thereof.

4. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising an open ended tube having itsdischarge end in the path of flow of fuel into said space, said tubehaving a side port intermediate the ends thereof and a plurality ofapertures between said port and said discharge end, and a burner firinginto said port whereby the gases spiral around in said tube beforeflowing from the discharge end thereof.

5. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising an open ended tube having itsdischarge end in the path of flow of fuel into said space, said tubehaving an enlarged chamber intermediate its ends, and a pressure burnerfiring into said chamber whereby the gases spiral around in said chamberbefore flowing from the discharge end of said tube, said confined spacecomprising a radiator tube having a suction producing device at itsdischarge end.

6. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising means forming a passage having aside opening and having a discharge end in the path of flow of fuel intosaid space, and a burner firing into said side opening whereby the gasesspiral around in said passage before emerging from the discharge endthereof, said confined space comprising a radiator tube having a suctionproducing device at its discharge end.

7. In combination, means for simultaneously flowing a stream of fuel anda stream of air into a confined space which is subject to draft,apparatus for maintaining ignition of said fuel irrespective ofpulsations in said space comprising means forming a passage having adischarge end in the path of flow of fuel into said space and having anenlarged chamber portion remote from said discharge end, and a burnerfiring tangentially into said chamber whereby the gases spiral around inthe chamber before emerging from the discharge end of said passage.

8. A burner apparatus comprising in combination a metallic drum, anannular fuel supply chamber intermediate the ends of said drum, arefractory lining within said drum and forming a flow passage therein, atubular body carried by and forming an extension of said drum, 2.plurality of tubes in communication with said fuel supply chamber andarranged to discharge adjacent the discharge end of said body, and apilot burner-dischcarging into said passage for supplychamber formed inthe casing intermediate theends thereof, a refractory lining within saidcasing and forming a passage therein, a tubular extension atone end ofsaid passage and forming a continuation thereof, said passage having anenlarged portion remote from said extension, a fuel supply tube incommunication with said annular chamber and arranged to dischargeadjacent the discharge end of said extension, and a pilotburnerdischarging its gases intothe enlarged portion or said passagewhereby to ignite the fuel flowing from said extension.

. 3 10. In apparatus for producing delayed combustion in a heatradiating tube which is subject to draft, the combination 01' astructure forming a combustion chamber outside of said tube, means i fordischarging a. preformed mixture or air and fuel into said chamber, ahot gas conduit leading from said chamber into the intake end of saidtube in radially spaced relation whereby to form 1 an annular airpassage between said tube and conduit, a source of fuel supply, andmeans for conducting said fuel from said source to a point in said tubebetween the walls of said conduit; 1

WILLIAM M, HEPBURN. THEODORE W. MUNFORD.

the latter and

